添加Li2O对陶瓷CBN砂轮结合剂性能的影响研究

本文主要研究了添加Li2O对Na2O-B2O3-Al2O3-SiO2陶瓷结合剂性能的影响.实验结果表明:随着Li2O添加量的增加,结合剂的耐火度显著降低;在0～6wt% Li2O添加量范围内,结合剂的耐火度下降较快,之后耐火度变化趋于平缓.随着Li2O添加量的增加,结合剂的高温流动性增大.随着温度升高,相同组成结合剂的流动性明显增大.当添加6% Li2O时,磨具试样的抗弯强度出现一个最大值.当Li2O添加量低于6wt%时,随着Li2O含量增大,结合剂玻化程度逐渐改善,结合剂与磨粒结合紧密,磨具试样的强度增大;Li2O含量高于6wt%时,会因结合剂本身结构的变化和磨具显微结构的变坏,使磨具强度降低.磨具显微结构与磨具强度变化有着一致的对应关系.

Effects of lithium on the properties of vitrified bond for CBN grinding wheel

The effects of Lithia additive on the properties of Na_2O-B_2O_3-Al_2O_3-SiO_2 vitrified bond were studied by means of refractoriness,fluidity,bending strength measurement and SEM analysis in this paper.The results showed that the refractoriness of vitrified bond decreased with the increase of Li_(2)O additive,and the refractoriness dropped quickly with the increasing of Li_(2)O when Li_(2)O content was below 6wt%,but its change became slow when Li_(2)O addition was over 6wt%.Its fluidity increased obviously with the increasing of Li_(2)O and the increasing of sintering temperature.The bending strength achieved a maximum with an addition of 6wt%Li_(2)O.The vitrification of the bond and the sintering of samples were improved and the strength was increased with the increasing of Li_(2)O when Li_(2)O addition was below 6wt%,while the microstructure of bond bridge became worse and the bonding strength was decreased with the increasing of Li_(2)O when Li_(2)O addition was over 6wt%.SEM micrographs showed good agreement with the change of the bending strength of samples.